Merge branch 'rs/fix-alt-odb-path-comparison' into maint
[git] / merge-recursive.c
1 /*
2  * Recursive Merge algorithm stolen from git-merge-recursive.py by
3  * Fredrik Kuivinen.
4  * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
5  */
6 #include "advice.h"
7 #include "cache.h"
8 #include "cache-tree.h"
9 #include "commit.h"
10 #include "blob.h"
11 #include "builtin.h"
12 #include "tree-walk.h"
13 #include "diff.h"
14 #include "diffcore.h"
15 #include "tag.h"
16 #include "unpack-trees.h"
17 #include "string-list.h"
18 #include "xdiff-interface.h"
19 #include "ll-merge.h"
20 #include "attr.h"
21 #include "merge-recursive.h"
22 #include "dir.h"
23 #include "submodule.h"
24
25 static struct tree *shift_tree_object(struct tree *one, struct tree *two,
26                                       const char *subtree_shift)
27 {
28         unsigned char shifted[20];
29
30         if (!*subtree_shift) {
31                 shift_tree(one->object.sha1, two->object.sha1, shifted, 0);
32         } else {
33                 shift_tree_by(one->object.sha1, two->object.sha1, shifted,
34                               subtree_shift);
35         }
36         if (!hashcmp(two->object.sha1, shifted))
37                 return two;
38         return lookup_tree(shifted);
39 }
40
41 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
42 {
43         struct commit *commit = alloc_commit_node();
44         struct merge_remote_desc *desc = xmalloc(sizeof(*desc));
45
46         desc->name = comment;
47         desc->obj = (struct object *)commit;
48         commit->tree = tree;
49         commit->util = desc;
50         commit->object.parsed = 1;
51         return commit;
52 }
53
54 /*
55  * Since we use get_tree_entry(), which does not put the read object into
56  * the object pool, we cannot rely on a == b.
57  */
58 static int sha_eq(const unsigned char *a, const unsigned char *b)
59 {
60         if (!a && !b)
61                 return 2;
62         return a && b && hashcmp(a, b) == 0;
63 }
64
65 enum rename_type {
66         RENAME_NORMAL = 0,
67         RENAME_DELETE,
68         RENAME_ONE_FILE_TO_ONE,
69         RENAME_ONE_FILE_TO_TWO,
70         RENAME_TWO_FILES_TO_ONE
71 };
72
73 struct rename_conflict_info {
74         enum rename_type rename_type;
75         struct diff_filepair *pair1;
76         struct diff_filepair *pair2;
77         const char *branch1;
78         const char *branch2;
79         struct stage_data *dst_entry1;
80         struct stage_data *dst_entry2;
81         struct diff_filespec ren1_other;
82         struct diff_filespec ren2_other;
83 };
84
85 /*
86  * Since we want to write the index eventually, we cannot reuse the index
87  * for these (temporary) data.
88  */
89 struct stage_data {
90         struct {
91                 unsigned mode;
92                 unsigned char sha[20];
93         } stages[4];
94         struct rename_conflict_info *rename_conflict_info;
95         unsigned processed:1;
96 };
97
98 static inline void setup_rename_conflict_info(enum rename_type rename_type,
99                                               struct diff_filepair *pair1,
100                                               struct diff_filepair *pair2,
101                                               const char *branch1,
102                                               const char *branch2,
103                                               struct stage_data *dst_entry1,
104                                               struct stage_data *dst_entry2,
105                                               struct merge_options *o,
106                                               struct stage_data *src_entry1,
107                                               struct stage_data *src_entry2)
108 {
109         struct rename_conflict_info *ci = xcalloc(1, sizeof(struct rename_conflict_info));
110         ci->rename_type = rename_type;
111         ci->pair1 = pair1;
112         ci->branch1 = branch1;
113         ci->branch2 = branch2;
114
115         ci->dst_entry1 = dst_entry1;
116         dst_entry1->rename_conflict_info = ci;
117         dst_entry1->processed = 0;
118
119         assert(!pair2 == !dst_entry2);
120         if (dst_entry2) {
121                 ci->dst_entry2 = dst_entry2;
122                 ci->pair2 = pair2;
123                 dst_entry2->rename_conflict_info = ci;
124         }
125
126         if (rename_type == RENAME_TWO_FILES_TO_ONE) {
127                 /*
128                  * For each rename, there could have been
129                  * modifications on the side of history where that
130                  * file was not renamed.
131                  */
132                 int ostage1 = o->branch1 == branch1 ? 3 : 2;
133                 int ostage2 = ostage1 ^ 1;
134
135                 ci->ren1_other.path = pair1->one->path;
136                 hashcpy(ci->ren1_other.sha1, src_entry1->stages[ostage1].sha);
137                 ci->ren1_other.mode = src_entry1->stages[ostage1].mode;
138
139                 ci->ren2_other.path = pair2->one->path;
140                 hashcpy(ci->ren2_other.sha1, src_entry2->stages[ostage2].sha);
141                 ci->ren2_other.mode = src_entry2->stages[ostage2].mode;
142         }
143 }
144
145 static int show(struct merge_options *o, int v)
146 {
147         return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
148 }
149
150 static void flush_output(struct merge_options *o)
151 {
152         if (o->obuf.len) {
153                 fputs(o->obuf.buf, stdout);
154                 strbuf_reset(&o->obuf);
155         }
156 }
157
158 __attribute__((format (printf, 3, 4)))
159 static void output(struct merge_options *o, int v, const char *fmt, ...)
160 {
161         va_list ap;
162
163         if (!show(o, v))
164                 return;
165
166         strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
167         memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
168         strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
169
170         va_start(ap, fmt);
171         strbuf_vaddf(&o->obuf, fmt, ap);
172         va_end(ap);
173
174         strbuf_add(&o->obuf, "\n", 1);
175         if (!o->buffer_output)
176                 flush_output(o);
177 }
178
179 static void output_commit_title(struct merge_options *o, struct commit *commit)
180 {
181         int i;
182         flush_output(o);
183         for (i = o->call_depth; i--;)
184                 fputs("  ", stdout);
185         if (commit->util)
186                 printf("virtual %s\n", merge_remote_util(commit)->name);
187         else {
188                 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
189                 if (parse_commit(commit) != 0)
190                         printf(_("(bad commit)\n"));
191                 else {
192                         const char *title;
193                         const char *msg = get_commit_buffer(commit, NULL);
194                         int len = find_commit_subject(msg, &title);
195                         if (len)
196                                 printf("%.*s\n", len, title);
197                         unuse_commit_buffer(commit, msg);
198                 }
199         }
200 }
201
202 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
203                 const char *path, int stage, int refresh, int options)
204 {
205         struct cache_entry *ce;
206         ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage,
207                               (refresh ? (CE_MATCH_REFRESH |
208                                           CE_MATCH_IGNORE_MISSING) : 0 ));
209         if (!ce)
210                 return error(_("addinfo_cache failed for path '%s'"), path);
211         return add_cache_entry(ce, options);
212 }
213
214 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
215 {
216         parse_tree(tree);
217         init_tree_desc(desc, tree->buffer, tree->size);
218 }
219
220 static int git_merge_trees(int index_only,
221                            struct tree *common,
222                            struct tree *head,
223                            struct tree *merge)
224 {
225         int rc;
226         struct tree_desc t[3];
227         struct unpack_trees_options opts;
228
229         memset(&opts, 0, sizeof(opts));
230         if (index_only)
231                 opts.index_only = 1;
232         else
233                 opts.update = 1;
234         opts.merge = 1;
235         opts.head_idx = 2;
236         opts.fn = threeway_merge;
237         opts.src_index = &the_index;
238         opts.dst_index = &the_index;
239         setup_unpack_trees_porcelain(&opts, "merge");
240
241         init_tree_desc_from_tree(t+0, common);
242         init_tree_desc_from_tree(t+1, head);
243         init_tree_desc_from_tree(t+2, merge);
244
245         rc = unpack_trees(3, t, &opts);
246         cache_tree_free(&active_cache_tree);
247         return rc;
248 }
249
250 struct tree *write_tree_from_memory(struct merge_options *o)
251 {
252         struct tree *result = NULL;
253
254         if (unmerged_cache()) {
255                 int i;
256                 fprintf(stderr, "BUG: There are unmerged index entries:\n");
257                 for (i = 0; i < active_nr; i++) {
258                         const struct cache_entry *ce = active_cache[i];
259                         if (ce_stage(ce))
260                                 fprintf(stderr, "BUG: %d %.*s\n", ce_stage(ce),
261                                         (int)ce_namelen(ce), ce->name);
262                 }
263                 die("Bug in merge-recursive.c");
264         }
265
266         if (!active_cache_tree)
267                 active_cache_tree = cache_tree();
268
269         if (!cache_tree_fully_valid(active_cache_tree) &&
270             cache_tree_update(active_cache_tree,
271                               (const struct cache_entry * const *)active_cache,
272                               active_nr, 0) < 0)
273                 die(_("error building trees"));
274
275         result = lookup_tree(active_cache_tree->sha1);
276
277         return result;
278 }
279
280 static int save_files_dirs(const unsigned char *sha1,
281                 const char *base, int baselen, const char *path,
282                 unsigned int mode, int stage, void *context)
283 {
284         int len = strlen(path);
285         char *newpath = xmalloc(baselen + len + 1);
286         struct merge_options *o = context;
287
288         memcpy(newpath, base, baselen);
289         memcpy(newpath + baselen, path, len);
290         newpath[baselen + len] = '\0';
291
292         if (S_ISDIR(mode))
293                 string_list_insert(&o->current_directory_set, newpath);
294         else
295                 string_list_insert(&o->current_file_set, newpath);
296         free(newpath);
297
298         return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
299 }
300
301 static int get_files_dirs(struct merge_options *o, struct tree *tree)
302 {
303         int n;
304         struct pathspec match_all;
305         memset(&match_all, 0, sizeof(match_all));
306         if (read_tree_recursive(tree, "", 0, 0, &match_all, save_files_dirs, o))
307                 return 0;
308         n = o->current_file_set.nr + o->current_directory_set.nr;
309         return n;
310 }
311
312 /*
313  * Returns an index_entry instance which doesn't have to correspond to
314  * a real cache entry in Git's index.
315  */
316 static struct stage_data *insert_stage_data(const char *path,
317                 struct tree *o, struct tree *a, struct tree *b,
318                 struct string_list *entries)
319 {
320         struct string_list_item *item;
321         struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
322         get_tree_entry(o->object.sha1, path,
323                         e->stages[1].sha, &e->stages[1].mode);
324         get_tree_entry(a->object.sha1, path,
325                         e->stages[2].sha, &e->stages[2].mode);
326         get_tree_entry(b->object.sha1, path,
327                         e->stages[3].sha, &e->stages[3].mode);
328         item = string_list_insert(entries, path);
329         item->util = e;
330         return e;
331 }
332
333 /*
334  * Create a dictionary mapping file names to stage_data objects. The
335  * dictionary contains one entry for every path with a non-zero stage entry.
336  */
337 static struct string_list *get_unmerged(void)
338 {
339         struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
340         int i;
341
342         unmerged->strdup_strings = 1;
343
344         for (i = 0; i < active_nr; i++) {
345                 struct string_list_item *item;
346                 struct stage_data *e;
347                 const struct cache_entry *ce = active_cache[i];
348                 if (!ce_stage(ce))
349                         continue;
350
351                 item = string_list_lookup(unmerged, ce->name);
352                 if (!item) {
353                         item = string_list_insert(unmerged, ce->name);
354                         item->util = xcalloc(1, sizeof(struct stage_data));
355                 }
356                 e = item->util;
357                 e->stages[ce_stage(ce)].mode = ce->ce_mode;
358                 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
359         }
360
361         return unmerged;
362 }
363
364 static int string_list_df_name_compare(const void *a, const void *b)
365 {
366         const struct string_list_item *one = a;
367         const struct string_list_item *two = b;
368         int onelen = strlen(one->string);
369         int twolen = strlen(two->string);
370         /*
371          * Here we only care that entries for D/F conflicts are
372          * adjacent, in particular with the file of the D/F conflict
373          * appearing before files below the corresponding directory.
374          * The order of the rest of the list is irrelevant for us.
375          *
376          * To achieve this, we sort with df_name_compare and provide
377          * the mode S_IFDIR so that D/F conflicts will sort correctly.
378          * We use the mode S_IFDIR for everything else for simplicity,
379          * since in other cases any changes in their order due to
380          * sorting cause no problems for us.
381          */
382         int cmp = df_name_compare(one->string, onelen, S_IFDIR,
383                                   two->string, twolen, S_IFDIR);
384         /*
385          * Now that 'foo' and 'foo/bar' compare equal, we have to make sure
386          * that 'foo' comes before 'foo/bar'.
387          */
388         if (cmp)
389                 return cmp;
390         return onelen - twolen;
391 }
392
393 static void record_df_conflict_files(struct merge_options *o,
394                                      struct string_list *entries)
395 {
396         /* If there is a D/F conflict and the file for such a conflict
397          * currently exist in the working tree, we want to allow it to be
398          * removed to make room for the corresponding directory if needed.
399          * The files underneath the directories of such D/F conflicts will
400          * be processed before the corresponding file involved in the D/F
401          * conflict.  If the D/F directory ends up being removed by the
402          * merge, then we won't have to touch the D/F file.  If the D/F
403          * directory needs to be written to the working copy, then the D/F
404          * file will simply be removed (in make_room_for_path()) to make
405          * room for the necessary paths.  Note that if both the directory
406          * and the file need to be present, then the D/F file will be
407          * reinstated with a new unique name at the time it is processed.
408          */
409         struct string_list df_sorted_entries;
410         const char *last_file = NULL;
411         int last_len = 0;
412         int i;
413
414         /*
415          * If we're merging merge-bases, we don't want to bother with
416          * any working directory changes.
417          */
418         if (o->call_depth)
419                 return;
420
421         /* Ensure D/F conflicts are adjacent in the entries list. */
422         memset(&df_sorted_entries, 0, sizeof(struct string_list));
423         for (i = 0; i < entries->nr; i++) {
424                 struct string_list_item *next = &entries->items[i];
425                 string_list_append(&df_sorted_entries, next->string)->util =
426                                    next->util;
427         }
428         qsort(df_sorted_entries.items, entries->nr, sizeof(*entries->items),
429               string_list_df_name_compare);
430
431         string_list_clear(&o->df_conflict_file_set, 1);
432         for (i = 0; i < df_sorted_entries.nr; i++) {
433                 const char *path = df_sorted_entries.items[i].string;
434                 int len = strlen(path);
435                 struct stage_data *e = df_sorted_entries.items[i].util;
436
437                 /*
438                  * Check if last_file & path correspond to a D/F conflict;
439                  * i.e. whether path is last_file+'/'+<something>.
440                  * If so, record that it's okay to remove last_file to make
441                  * room for path and friends if needed.
442                  */
443                 if (last_file &&
444                     len > last_len &&
445                     memcmp(path, last_file, last_len) == 0 &&
446                     path[last_len] == '/') {
447                         string_list_insert(&o->df_conflict_file_set, last_file);
448                 }
449
450                 /*
451                  * Determine whether path could exist as a file in the
452                  * working directory as a possible D/F conflict.  This
453                  * will only occur when it exists in stage 2 as a
454                  * file.
455                  */
456                 if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
457                         last_file = path;
458                         last_len = len;
459                 } else {
460                         last_file = NULL;
461                 }
462         }
463         string_list_clear(&df_sorted_entries, 0);
464 }
465
466 struct rename {
467         struct diff_filepair *pair;
468         struct stage_data *src_entry;
469         struct stage_data *dst_entry;
470         unsigned processed:1;
471 };
472
473 /*
474  * Get information of all renames which occurred between 'o_tree' and
475  * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
476  * 'b_tree') to be able to associate the correct cache entries with
477  * the rename information. 'tree' is always equal to either a_tree or b_tree.
478  */
479 static struct string_list *get_renames(struct merge_options *o,
480                                        struct tree *tree,
481                                        struct tree *o_tree,
482                                        struct tree *a_tree,
483                                        struct tree *b_tree,
484                                        struct string_list *entries)
485 {
486         int i;
487         struct string_list *renames;
488         struct diff_options opts;
489
490         renames = xcalloc(1, sizeof(struct string_list));
491         diff_setup(&opts);
492         DIFF_OPT_SET(&opts, RECURSIVE);
493         DIFF_OPT_CLR(&opts, RENAME_EMPTY);
494         opts.detect_rename = DIFF_DETECT_RENAME;
495         opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
496                             o->diff_rename_limit >= 0 ? o->diff_rename_limit :
497                             1000;
498         opts.rename_score = o->rename_score;
499         opts.show_rename_progress = o->show_rename_progress;
500         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
501         diff_setup_done(&opts);
502         diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
503         diffcore_std(&opts);
504         if (opts.needed_rename_limit > o->needed_rename_limit)
505                 o->needed_rename_limit = opts.needed_rename_limit;
506         for (i = 0; i < diff_queued_diff.nr; ++i) {
507                 struct string_list_item *item;
508                 struct rename *re;
509                 struct diff_filepair *pair = diff_queued_diff.queue[i];
510                 if (pair->status != 'R') {
511                         diff_free_filepair(pair);
512                         continue;
513                 }
514                 re = xmalloc(sizeof(*re));
515                 re->processed = 0;
516                 re->pair = pair;
517                 item = string_list_lookup(entries, re->pair->one->path);
518                 if (!item)
519                         re->src_entry = insert_stage_data(re->pair->one->path,
520                                         o_tree, a_tree, b_tree, entries);
521                 else
522                         re->src_entry = item->util;
523
524                 item = string_list_lookup(entries, re->pair->two->path);
525                 if (!item)
526                         re->dst_entry = insert_stage_data(re->pair->two->path,
527                                         o_tree, a_tree, b_tree, entries);
528                 else
529                         re->dst_entry = item->util;
530                 item = string_list_insert(renames, pair->one->path);
531                 item->util = re;
532         }
533         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
534         diff_queued_diff.nr = 0;
535         diff_flush(&opts);
536         return renames;
537 }
538
539 static int update_stages(const char *path, const struct diff_filespec *o,
540                          const struct diff_filespec *a,
541                          const struct diff_filespec *b)
542 {
543
544         /*
545          * NOTE: It is usually a bad idea to call update_stages on a path
546          * before calling update_file on that same path, since it can
547          * sometimes lead to spurious "refusing to lose untracked file..."
548          * messages from update_file (via make_room_for path via
549          * would_lose_untracked).  Instead, reverse the order of the calls
550          * (executing update_file first and then update_stages).
551          */
552         int clear = 1;
553         int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
554         if (clear)
555                 if (remove_file_from_cache(path))
556                         return -1;
557         if (o)
558                 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
559                         return -1;
560         if (a)
561                 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
562                         return -1;
563         if (b)
564                 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
565                         return -1;
566         return 0;
567 }
568
569 static void update_entry(struct stage_data *entry,
570                          struct diff_filespec *o,
571                          struct diff_filespec *a,
572                          struct diff_filespec *b)
573 {
574         entry->processed = 0;
575         entry->stages[1].mode = o->mode;
576         entry->stages[2].mode = a->mode;
577         entry->stages[3].mode = b->mode;
578         hashcpy(entry->stages[1].sha, o->sha1);
579         hashcpy(entry->stages[2].sha, a->sha1);
580         hashcpy(entry->stages[3].sha, b->sha1);
581 }
582
583 static int remove_file(struct merge_options *o, int clean,
584                        const char *path, int no_wd)
585 {
586         int update_cache = o->call_depth || clean;
587         int update_working_directory = !o->call_depth && !no_wd;
588
589         if (update_cache) {
590                 if (remove_file_from_cache(path))
591                         return -1;
592         }
593         if (update_working_directory) {
594                 if (ignore_case) {
595                         struct cache_entry *ce;
596                         ce = cache_file_exists(path, strlen(path), ignore_case);
597                         if (ce && ce_stage(ce) == 0)
598                                 return 0;
599                 }
600                 if (remove_path(path))
601                         return -1;
602         }
603         return 0;
604 }
605
606 static char *unique_path(struct merge_options *o, const char *path, const char *branch)
607 {
608         char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
609         int suffix = 0;
610         struct stat st;
611         char *p = newpath + strlen(path);
612         strcpy(newpath, path);
613         *(p++) = '~';
614         strcpy(p, branch);
615         for (; *p; ++p)
616                 if ('/' == *p)
617                         *p = '_';
618         while (string_list_has_string(&o->current_file_set, newpath) ||
619                string_list_has_string(&o->current_directory_set, newpath) ||
620                lstat(newpath, &st) == 0)
621                 sprintf(p, "_%d", suffix++);
622
623         string_list_insert(&o->current_file_set, newpath);
624         return newpath;
625 }
626
627 static int dir_in_way(const char *path, int check_working_copy)
628 {
629         int pos, pathlen = strlen(path);
630         char *dirpath = xmalloc(pathlen + 2);
631         struct stat st;
632
633         strcpy(dirpath, path);
634         dirpath[pathlen] = '/';
635         dirpath[pathlen+1] = '\0';
636
637         pos = cache_name_pos(dirpath, pathlen+1);
638
639         if (pos < 0)
640                 pos = -1 - pos;
641         if (pos < active_nr &&
642             !strncmp(dirpath, active_cache[pos]->name, pathlen+1)) {
643                 free(dirpath);
644                 return 1;
645         }
646
647         free(dirpath);
648         return check_working_copy && !lstat(path, &st) && S_ISDIR(st.st_mode);
649 }
650
651 static int was_tracked(const char *path)
652 {
653         int pos = cache_name_pos(path, strlen(path));
654
655         if (pos < 0)
656                 pos = -1 - pos;
657         while (pos < active_nr &&
658                !strcmp(path, active_cache[pos]->name)) {
659                 /*
660                  * If stage #0, it is definitely tracked.
661                  * If it has stage #2 then it was tracked
662                  * before this merge started.  All other
663                  * cases the path was not tracked.
664                  */
665                 switch (ce_stage(active_cache[pos])) {
666                 case 0:
667                 case 2:
668                         return 1;
669                 }
670                 pos++;
671         }
672         return 0;
673 }
674
675 static int would_lose_untracked(const char *path)
676 {
677         return !was_tracked(path) && file_exists(path);
678 }
679
680 static int make_room_for_path(struct merge_options *o, const char *path)
681 {
682         int status, i;
683         const char *msg = _("failed to create path '%s'%s");
684
685         /* Unlink any D/F conflict files that are in the way */
686         for (i = 0; i < o->df_conflict_file_set.nr; i++) {
687                 const char *df_path = o->df_conflict_file_set.items[i].string;
688                 size_t pathlen = strlen(path);
689                 size_t df_pathlen = strlen(df_path);
690                 if (df_pathlen < pathlen &&
691                     path[df_pathlen] == '/' &&
692                     strncmp(path, df_path, df_pathlen) == 0) {
693                         output(o, 3,
694                                _("Removing %s to make room for subdirectory\n"),
695                                df_path);
696                         unlink(df_path);
697                         unsorted_string_list_delete_item(&o->df_conflict_file_set,
698                                                          i, 0);
699                         break;
700                 }
701         }
702
703         /* Make sure leading directories are created */
704         status = safe_create_leading_directories_const(path);
705         if (status) {
706                 if (status == SCLD_EXISTS) {
707                         /* something else exists */
708                         error(msg, path, _(": perhaps a D/F conflict?"));
709                         return -1;
710                 }
711                 die(msg, path, "");
712         }
713
714         /*
715          * Do not unlink a file in the work tree if we are not
716          * tracking it.
717          */
718         if (would_lose_untracked(path))
719                 return error(_("refusing to lose untracked file at '%s'"),
720                              path);
721
722         /* Successful unlink is good.. */
723         if (!unlink(path))
724                 return 0;
725         /* .. and so is no existing file */
726         if (errno == ENOENT)
727                 return 0;
728         /* .. but not some other error (who really cares what?) */
729         return error(msg, path, _(": perhaps a D/F conflict?"));
730 }
731
732 static void update_file_flags(struct merge_options *o,
733                               const unsigned char *sha,
734                               unsigned mode,
735                               const char *path,
736                               int update_cache,
737                               int update_wd)
738 {
739         if (o->call_depth)
740                 update_wd = 0;
741
742         if (update_wd) {
743                 enum object_type type;
744                 void *buf;
745                 unsigned long size;
746
747                 if (S_ISGITLINK(mode)) {
748                         /*
749                          * We may later decide to recursively descend into
750                          * the submodule directory and update its index
751                          * and/or work tree, but we do not do that now.
752                          */
753                         update_wd = 0;
754                         goto update_index;
755                 }
756
757                 buf = read_sha1_file(sha, &type, &size);
758                 if (!buf)
759                         die(_("cannot read object %s '%s'"), sha1_to_hex(sha), path);
760                 if (type != OBJ_BLOB)
761                         die(_("blob expected for %s '%s'"), sha1_to_hex(sha), path);
762                 if (S_ISREG(mode)) {
763                         struct strbuf strbuf = STRBUF_INIT;
764                         if (convert_to_working_tree(path, buf, size, &strbuf)) {
765                                 free(buf);
766                                 size = strbuf.len;
767                                 buf = strbuf_detach(&strbuf, NULL);
768                         }
769                 }
770
771                 if (make_room_for_path(o, path) < 0) {
772                         update_wd = 0;
773                         free(buf);
774                         goto update_index;
775                 }
776                 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
777                         int fd;
778                         if (mode & 0100)
779                                 mode = 0777;
780                         else
781                                 mode = 0666;
782                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
783                         if (fd < 0)
784                                 die_errno(_("failed to open '%s'"), path);
785                         write_in_full(fd, buf, size);
786                         close(fd);
787                 } else if (S_ISLNK(mode)) {
788                         char *lnk = xmemdupz(buf, size);
789                         safe_create_leading_directories_const(path);
790                         unlink(path);
791                         if (symlink(lnk, path))
792                                 die_errno(_("failed to symlink '%s'"), path);
793                         free(lnk);
794                 } else
795                         die(_("do not know what to do with %06o %s '%s'"),
796                             mode, sha1_to_hex(sha), path);
797                 free(buf);
798         }
799  update_index:
800         if (update_cache)
801                 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
802 }
803
804 static void update_file(struct merge_options *o,
805                         int clean,
806                         const unsigned char *sha,
807                         unsigned mode,
808                         const char *path)
809 {
810         update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
811 }
812
813 /* Low level file merging, update and removal */
814
815 struct merge_file_info {
816         unsigned char sha[20];
817         unsigned mode;
818         unsigned clean:1,
819                  merge:1;
820 };
821
822 static int merge_3way(struct merge_options *o,
823                       mmbuffer_t *result_buf,
824                       const struct diff_filespec *one,
825                       const struct diff_filespec *a,
826                       const struct diff_filespec *b,
827                       const char *branch1,
828                       const char *branch2)
829 {
830         mmfile_t orig, src1, src2;
831         struct ll_merge_options ll_opts = {0};
832         char *base_name, *name1, *name2;
833         int merge_status;
834
835         ll_opts.renormalize = o->renormalize;
836         ll_opts.xdl_opts = o->xdl_opts;
837
838         if (o->call_depth) {
839                 ll_opts.virtual_ancestor = 1;
840                 ll_opts.variant = 0;
841         } else {
842                 switch (o->recursive_variant) {
843                 case MERGE_RECURSIVE_OURS:
844                         ll_opts.variant = XDL_MERGE_FAVOR_OURS;
845                         break;
846                 case MERGE_RECURSIVE_THEIRS:
847                         ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
848                         break;
849                 default:
850                         ll_opts.variant = 0;
851                         break;
852                 }
853         }
854
855         if (strcmp(a->path, b->path) ||
856             (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
857                 base_name = o->ancestor == NULL ? NULL :
858                         mkpathdup("%s:%s", o->ancestor, one->path);
859                 name1 = mkpathdup("%s:%s", branch1, a->path);
860                 name2 = mkpathdup("%s:%s", branch2, b->path);
861         } else {
862                 base_name = o->ancestor == NULL ? NULL :
863                         mkpathdup("%s", o->ancestor);
864                 name1 = mkpathdup("%s", branch1);
865                 name2 = mkpathdup("%s", branch2);
866         }
867
868         read_mmblob(&orig, one->sha1);
869         read_mmblob(&src1, a->sha1);
870         read_mmblob(&src2, b->sha1);
871
872         merge_status = ll_merge(result_buf, a->path, &orig, base_name,
873                                 &src1, name1, &src2, name2, &ll_opts);
874
875         free(base_name);
876         free(name1);
877         free(name2);
878         free(orig.ptr);
879         free(src1.ptr);
880         free(src2.ptr);
881         return merge_status;
882 }
883
884 static struct merge_file_info merge_file_1(struct merge_options *o,
885                                            const struct diff_filespec *one,
886                                            const struct diff_filespec *a,
887                                            const struct diff_filespec *b,
888                                            const char *branch1,
889                                            const char *branch2)
890 {
891         struct merge_file_info result;
892         result.merge = 0;
893         result.clean = 1;
894
895         if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
896                 result.clean = 0;
897                 if (S_ISREG(a->mode)) {
898                         result.mode = a->mode;
899                         hashcpy(result.sha, a->sha1);
900                 } else {
901                         result.mode = b->mode;
902                         hashcpy(result.sha, b->sha1);
903                 }
904         } else {
905                 if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
906                         result.merge = 1;
907
908                 /*
909                  * Merge modes
910                  */
911                 if (a->mode == b->mode || a->mode == one->mode)
912                         result.mode = b->mode;
913                 else {
914                         result.mode = a->mode;
915                         if (b->mode != one->mode) {
916                                 result.clean = 0;
917                                 result.merge = 1;
918                         }
919                 }
920
921                 if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
922                         hashcpy(result.sha, b->sha1);
923                 else if (sha_eq(b->sha1, one->sha1))
924                         hashcpy(result.sha, a->sha1);
925                 else if (S_ISREG(a->mode)) {
926                         mmbuffer_t result_buf;
927                         int merge_status;
928
929                         merge_status = merge_3way(o, &result_buf, one, a, b,
930                                                   branch1, branch2);
931
932                         if ((merge_status < 0) || !result_buf.ptr)
933                                 die(_("Failed to execute internal merge"));
934
935                         if (write_sha1_file(result_buf.ptr, result_buf.size,
936                                             blob_type, result.sha))
937                                 die(_("Unable to add %s to database"),
938                                     a->path);
939
940                         free(result_buf.ptr);
941                         result.clean = (merge_status == 0);
942                 } else if (S_ISGITLINK(a->mode)) {
943                         result.clean = merge_submodule(result.sha,
944                                                        one->path, one->sha1,
945                                                        a->sha1, b->sha1,
946                                                        !o->call_depth);
947                 } else if (S_ISLNK(a->mode)) {
948                         hashcpy(result.sha, a->sha1);
949
950                         if (!sha_eq(a->sha1, b->sha1))
951                                 result.clean = 0;
952                 } else {
953                         die(_("unsupported object type in the tree"));
954                 }
955         }
956
957         return result;
958 }
959
960 static struct merge_file_info
961 merge_file_special_markers(struct merge_options *o,
962                            const struct diff_filespec *one,
963                            const struct diff_filespec *a,
964                            const struct diff_filespec *b,
965                            const char *branch1,
966                            const char *filename1,
967                            const char *branch2,
968                            const char *filename2)
969 {
970         char *side1 = NULL;
971         char *side2 = NULL;
972         struct merge_file_info mfi;
973
974         if (filename1) {
975                 side1 = xmalloc(strlen(branch1) + strlen(filename1) + 2);
976                 sprintf(side1, "%s:%s", branch1, filename1);
977         }
978         if (filename2) {
979                 side2 = xmalloc(strlen(branch2) + strlen(filename2) + 2);
980                 sprintf(side2, "%s:%s", branch2, filename2);
981         }
982
983         mfi = merge_file_1(o, one, a, b,
984                            side1 ? side1 : branch1, side2 ? side2 : branch2);
985         free(side1);
986         free(side2);
987         return mfi;
988 }
989
990 static struct merge_file_info merge_file_one(struct merge_options *o,
991                                          const char *path,
992                                          const unsigned char *o_sha, int o_mode,
993                                          const unsigned char *a_sha, int a_mode,
994                                          const unsigned char *b_sha, int b_mode,
995                                          const char *branch1,
996                                          const char *branch2)
997 {
998         struct diff_filespec one, a, b;
999
1000         one.path = a.path = b.path = (char *)path;
1001         hashcpy(one.sha1, o_sha);
1002         one.mode = o_mode;
1003         hashcpy(a.sha1, a_sha);
1004         a.mode = a_mode;
1005         hashcpy(b.sha1, b_sha);
1006         b.mode = b_mode;
1007         return merge_file_1(o, &one, &a, &b, branch1, branch2);
1008 }
1009
1010 static void handle_change_delete(struct merge_options *o,
1011                                  const char *path,
1012                                  const unsigned char *o_sha, int o_mode,
1013                                  const unsigned char *a_sha, int a_mode,
1014                                  const unsigned char *b_sha, int b_mode,
1015                                  const char *change, const char *change_past)
1016 {
1017         char *renamed = NULL;
1018         if (dir_in_way(path, !o->call_depth)) {
1019                 renamed = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
1020         }
1021
1022         if (o->call_depth) {
1023                 /*
1024                  * We cannot arbitrarily accept either a_sha or b_sha as
1025                  * correct; since there is no true "middle point" between
1026                  * them, simply reuse the base version for virtual merge base.
1027                  */
1028                 remove_file_from_cache(path);
1029                 update_file(o, 0, o_sha, o_mode, renamed ? renamed : path);
1030         } else if (!a_sha) {
1031                 if (!renamed) {
1032                         output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1033                                "and %s in %s. Version %s of %s left in tree."),
1034                                change, path, o->branch1, change_past,
1035                                o->branch2, o->branch2, path);
1036                         update_file(o, 0, b_sha, b_mode, path);
1037                 } else {
1038                         output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1039                                "and %s in %s. Version %s of %s left in tree at %s."),
1040                                change, path, o->branch1, change_past,
1041                                o->branch2, o->branch2, path, renamed);
1042                         update_file(o, 0, b_sha, b_mode, renamed);
1043                 }
1044         } else {
1045                 if (!renamed) {
1046                         output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1047                                "and %s in %s. Version %s of %s left in tree."),
1048                                change, path, o->branch2, change_past,
1049                                o->branch1, o->branch1, path);
1050                 } else {
1051                         output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1052                                "and %s in %s. Version %s of %s left in tree at %s."),
1053                                change, path, o->branch2, change_past,
1054                                o->branch1, o->branch1, path, renamed);
1055                         update_file(o, 0, a_sha, a_mode, renamed);
1056                 }
1057                 /*
1058                  * No need to call update_file() on path when !renamed, since
1059                  * that would needlessly touch path.  We could call
1060                  * update_file_flags() with update_cache=0 and update_wd=0,
1061                  * but that's a no-op.
1062                  */
1063         }
1064         free(renamed);
1065 }
1066
1067 static void conflict_rename_delete(struct merge_options *o,
1068                                    struct diff_filepair *pair,
1069                                    const char *rename_branch,
1070                                    const char *other_branch)
1071 {
1072         const struct diff_filespec *orig = pair->one;
1073         const struct diff_filespec *dest = pair->two;
1074         const unsigned char *a_sha = NULL;
1075         const unsigned char *b_sha = NULL;
1076         int a_mode = 0;
1077         int b_mode = 0;
1078
1079         if (rename_branch == o->branch1) {
1080                 a_sha = dest->sha1;
1081                 a_mode = dest->mode;
1082         } else {
1083                 b_sha = dest->sha1;
1084                 b_mode = dest->mode;
1085         }
1086
1087         handle_change_delete(o,
1088                              o->call_depth ? orig->path : dest->path,
1089                              orig->sha1, orig->mode,
1090                              a_sha, a_mode,
1091                              b_sha, b_mode,
1092                              _("rename"), _("renamed"));
1093
1094         if (o->call_depth) {
1095                 remove_file_from_cache(dest->path);
1096         } else {
1097                 update_stages(dest->path, NULL,
1098                               rename_branch == o->branch1 ? dest : NULL,
1099                               rename_branch == o->branch1 ? NULL : dest);
1100         }
1101
1102 }
1103
1104 static struct diff_filespec *filespec_from_entry(struct diff_filespec *target,
1105                                                  struct stage_data *entry,
1106                                                  int stage)
1107 {
1108         unsigned char *sha = entry->stages[stage].sha;
1109         unsigned mode = entry->stages[stage].mode;
1110         if (mode == 0 || is_null_sha1(sha))
1111                 return NULL;
1112         hashcpy(target->sha1, sha);
1113         target->mode = mode;
1114         return target;
1115 }
1116
1117 static void handle_file(struct merge_options *o,
1118                         struct diff_filespec *rename,
1119                         int stage,
1120                         struct rename_conflict_info *ci)
1121 {
1122         char *dst_name = rename->path;
1123         struct stage_data *dst_entry;
1124         const char *cur_branch, *other_branch;
1125         struct diff_filespec other;
1126         struct diff_filespec *add;
1127
1128         if (stage == 2) {
1129                 dst_entry = ci->dst_entry1;
1130                 cur_branch = ci->branch1;
1131                 other_branch = ci->branch2;
1132         } else {
1133                 dst_entry = ci->dst_entry2;
1134                 cur_branch = ci->branch2;
1135                 other_branch = ci->branch1;
1136         }
1137
1138         add = filespec_from_entry(&other, dst_entry, stage ^ 1);
1139         if (add) {
1140                 char *add_name = unique_path(o, rename->path, other_branch);
1141                 update_file(o, 0, add->sha1, add->mode, add_name);
1142
1143                 remove_file(o, 0, rename->path, 0);
1144                 dst_name = unique_path(o, rename->path, cur_branch);
1145         } else {
1146                 if (dir_in_way(rename->path, !o->call_depth)) {
1147                         dst_name = unique_path(o, rename->path, cur_branch);
1148                         output(o, 1, _("%s is a directory in %s adding as %s instead"),
1149                                rename->path, other_branch, dst_name);
1150                 }
1151         }
1152         update_file(o, 0, rename->sha1, rename->mode, dst_name);
1153         if (stage == 2)
1154                 update_stages(rename->path, NULL, rename, add);
1155         else
1156                 update_stages(rename->path, NULL, add, rename);
1157
1158         if (dst_name != rename->path)
1159                 free(dst_name);
1160 }
1161
1162 static void conflict_rename_rename_1to2(struct merge_options *o,
1163                                         struct rename_conflict_info *ci)
1164 {
1165         /* One file was renamed in both branches, but to different names. */
1166         struct diff_filespec *one = ci->pair1->one;
1167         struct diff_filespec *a = ci->pair1->two;
1168         struct diff_filespec *b = ci->pair2->two;
1169
1170         output(o, 1, _("CONFLICT (rename/rename): "
1171                "Rename \"%s\"->\"%s\" in branch \"%s\" "
1172                "rename \"%s\"->\"%s\" in \"%s\"%s"),
1173                one->path, a->path, ci->branch1,
1174                one->path, b->path, ci->branch2,
1175                o->call_depth ? _(" (left unresolved)") : "");
1176         if (o->call_depth) {
1177                 struct merge_file_info mfi;
1178                 struct diff_filespec other;
1179                 struct diff_filespec *add;
1180                 mfi = merge_file_one(o, one->path,
1181                                  one->sha1, one->mode,
1182                                  a->sha1, a->mode,
1183                                  b->sha1, b->mode,
1184                                  ci->branch1, ci->branch2);
1185                 /*
1186                  * FIXME: For rename/add-source conflicts (if we could detect
1187                  * such), this is wrong.  We should instead find a unique
1188                  * pathname and then either rename the add-source file to that
1189                  * unique path, or use that unique path instead of src here.
1190                  */
1191                 update_file(o, 0, mfi.sha, mfi.mode, one->path);
1192
1193                 /*
1194                  * Above, we put the merged content at the merge-base's
1195                  * path.  Now we usually need to delete both a->path and
1196                  * b->path.  However, the rename on each side of the merge
1197                  * could also be involved in a rename/add conflict.  In
1198                  * such cases, we should keep the added file around,
1199                  * resolving the conflict at that path in its favor.
1200                  */
1201                 add = filespec_from_entry(&other, ci->dst_entry1, 2 ^ 1);
1202                 if (add)
1203                         update_file(o, 0, add->sha1, add->mode, a->path);
1204                 else
1205                         remove_file_from_cache(a->path);
1206                 add = filespec_from_entry(&other, ci->dst_entry2, 3 ^ 1);
1207                 if (add)
1208                         update_file(o, 0, add->sha1, add->mode, b->path);
1209                 else
1210                         remove_file_from_cache(b->path);
1211         } else {
1212                 handle_file(o, a, 2, ci);
1213                 handle_file(o, b, 3, ci);
1214         }
1215 }
1216
1217 static void conflict_rename_rename_2to1(struct merge_options *o,
1218                                         struct rename_conflict_info *ci)
1219 {
1220         /* Two files, a & b, were renamed to the same thing, c. */
1221         struct diff_filespec *a = ci->pair1->one;
1222         struct diff_filespec *b = ci->pair2->one;
1223         struct diff_filespec *c1 = ci->pair1->two;
1224         struct diff_filespec *c2 = ci->pair2->two;
1225         char *path = c1->path; /* == c2->path */
1226         struct merge_file_info mfi_c1;
1227         struct merge_file_info mfi_c2;
1228
1229         output(o, 1, _("CONFLICT (rename/rename): "
1230                "Rename %s->%s in %s. "
1231                "Rename %s->%s in %s"),
1232                a->path, c1->path, ci->branch1,
1233                b->path, c2->path, ci->branch2);
1234
1235         remove_file(o, 1, a->path, would_lose_untracked(a->path));
1236         remove_file(o, 1, b->path, would_lose_untracked(b->path));
1237
1238         mfi_c1 = merge_file_special_markers(o, a, c1, &ci->ren1_other,
1239                                             o->branch1, c1->path,
1240                                             o->branch2, ci->ren1_other.path);
1241         mfi_c2 = merge_file_special_markers(o, b, &ci->ren2_other, c2,
1242                                             o->branch1, ci->ren2_other.path,
1243                                             o->branch2, c2->path);
1244
1245         if (o->call_depth) {
1246                 /*
1247                  * If mfi_c1.clean && mfi_c2.clean, then it might make
1248                  * sense to do a two-way merge of those results.  But, I
1249                  * think in all cases, it makes sense to have the virtual
1250                  * merge base just undo the renames; they can be detected
1251                  * again later for the non-recursive merge.
1252                  */
1253                 remove_file(o, 0, path, 0);
1254                 update_file(o, 0, mfi_c1.sha, mfi_c1.mode, a->path);
1255                 update_file(o, 0, mfi_c2.sha, mfi_c2.mode, b->path);
1256         } else {
1257                 char *new_path1 = unique_path(o, path, ci->branch1);
1258                 char *new_path2 = unique_path(o, path, ci->branch2);
1259                 output(o, 1, _("Renaming %s to %s and %s to %s instead"),
1260                        a->path, new_path1, b->path, new_path2);
1261                 remove_file(o, 0, path, 0);
1262                 update_file(o, 0, mfi_c1.sha, mfi_c1.mode, new_path1);
1263                 update_file(o, 0, mfi_c2.sha, mfi_c2.mode, new_path2);
1264                 free(new_path2);
1265                 free(new_path1);
1266         }
1267 }
1268
1269 static int process_renames(struct merge_options *o,
1270                            struct string_list *a_renames,
1271                            struct string_list *b_renames)
1272 {
1273         int clean_merge = 1, i, j;
1274         struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
1275         struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
1276         const struct rename *sre;
1277
1278         for (i = 0; i < a_renames->nr; i++) {
1279                 sre = a_renames->items[i].util;
1280                 string_list_insert(&a_by_dst, sre->pair->two->path)->util
1281                         = (void *)sre;
1282         }
1283         for (i = 0; i < b_renames->nr; i++) {
1284                 sre = b_renames->items[i].util;
1285                 string_list_insert(&b_by_dst, sre->pair->two->path)->util
1286                         = (void *)sre;
1287         }
1288
1289         for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
1290                 struct string_list *renames1, *renames2Dst;
1291                 struct rename *ren1 = NULL, *ren2 = NULL;
1292                 const char *branch1, *branch2;
1293                 const char *ren1_src, *ren1_dst;
1294                 struct string_list_item *lookup;
1295
1296                 if (i >= a_renames->nr) {
1297                         ren2 = b_renames->items[j++].util;
1298                 } else if (j >= b_renames->nr) {
1299                         ren1 = a_renames->items[i++].util;
1300                 } else {
1301                         int compare = strcmp(a_renames->items[i].string,
1302                                              b_renames->items[j].string);
1303                         if (compare <= 0)
1304                                 ren1 = a_renames->items[i++].util;
1305                         if (compare >= 0)
1306                                 ren2 = b_renames->items[j++].util;
1307                 }
1308
1309                 /* TODO: refactor, so that 1/2 are not needed */
1310                 if (ren1) {
1311                         renames1 = a_renames;
1312                         renames2Dst = &b_by_dst;
1313                         branch1 = o->branch1;
1314                         branch2 = o->branch2;
1315                 } else {
1316                         struct rename *tmp;
1317                         renames1 = b_renames;
1318                         renames2Dst = &a_by_dst;
1319                         branch1 = o->branch2;
1320                         branch2 = o->branch1;
1321                         tmp = ren2;
1322                         ren2 = ren1;
1323                         ren1 = tmp;
1324                 }
1325
1326                 if (ren1->processed)
1327                         continue;
1328                 ren1->processed = 1;
1329                 ren1->dst_entry->processed = 1;
1330                 /* BUG: We should only mark src_entry as processed if we
1331                  * are not dealing with a rename + add-source case.
1332                  */
1333                 ren1->src_entry->processed = 1;
1334
1335                 ren1_src = ren1->pair->one->path;
1336                 ren1_dst = ren1->pair->two->path;
1337
1338                 if (ren2) {
1339                         /* One file renamed on both sides */
1340                         const char *ren2_src = ren2->pair->one->path;
1341                         const char *ren2_dst = ren2->pair->two->path;
1342                         enum rename_type rename_type;
1343                         if (strcmp(ren1_src, ren2_src) != 0)
1344                                 die("ren1_src != ren2_src");
1345                         ren2->dst_entry->processed = 1;
1346                         ren2->processed = 1;
1347                         if (strcmp(ren1_dst, ren2_dst) != 0) {
1348                                 rename_type = RENAME_ONE_FILE_TO_TWO;
1349                                 clean_merge = 0;
1350                         } else {
1351                                 rename_type = RENAME_ONE_FILE_TO_ONE;
1352                                 /* BUG: We should only remove ren1_src in
1353                                  * the base stage (think of rename +
1354                                  * add-source cases).
1355                                  */
1356                                 remove_file(o, 1, ren1_src, 1);
1357                                 update_entry(ren1->dst_entry,
1358                                              ren1->pair->one,
1359                                              ren1->pair->two,
1360                                              ren2->pair->two);
1361                         }
1362                         setup_rename_conflict_info(rename_type,
1363                                                    ren1->pair,
1364                                                    ren2->pair,
1365                                                    branch1,
1366                                                    branch2,
1367                                                    ren1->dst_entry,
1368                                                    ren2->dst_entry,
1369                                                    o,
1370                                                    NULL,
1371                                                    NULL);
1372                 } else if ((lookup = string_list_lookup(renames2Dst, ren1_dst))) {
1373                         /* Two different files renamed to the same thing */
1374                         char *ren2_dst;
1375                         ren2 = lookup->util;
1376                         ren2_dst = ren2->pair->two->path;
1377                         if (strcmp(ren1_dst, ren2_dst) != 0)
1378                                 die("ren1_dst != ren2_dst");
1379
1380                         clean_merge = 0;
1381                         ren2->processed = 1;
1382                         /*
1383                          * BUG: We should only mark src_entry as processed
1384                          * if we are not dealing with a rename + add-source
1385                          * case.
1386                          */
1387                         ren2->src_entry->processed = 1;
1388
1389                         setup_rename_conflict_info(RENAME_TWO_FILES_TO_ONE,
1390                                                    ren1->pair,
1391                                                    ren2->pair,
1392                                                    branch1,
1393                                                    branch2,
1394                                                    ren1->dst_entry,
1395                                                    ren2->dst_entry,
1396                                                    o,
1397                                                    ren1->src_entry,
1398                                                    ren2->src_entry);
1399
1400                 } else {
1401                         /* Renamed in 1, maybe changed in 2 */
1402                         /* we only use sha1 and mode of these */
1403                         struct diff_filespec src_other, dst_other;
1404                         int try_merge;
1405
1406                         /*
1407                          * unpack_trees loads entries from common-commit
1408                          * into stage 1, from head-commit into stage 2, and
1409                          * from merge-commit into stage 3.  We keep track
1410                          * of which side corresponds to the rename.
1411                          */
1412                         int renamed_stage = a_renames == renames1 ? 2 : 3;
1413                         int other_stage =   a_renames == renames1 ? 3 : 2;
1414
1415                         /* BUG: We should only remove ren1_src in the base
1416                          * stage and in other_stage (think of rename +
1417                          * add-source case).
1418                          */
1419                         remove_file(o, 1, ren1_src,
1420                                     renamed_stage == 2 || !was_tracked(ren1_src));
1421
1422                         hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
1423                         src_other.mode = ren1->src_entry->stages[other_stage].mode;
1424                         hashcpy(dst_other.sha1, ren1->dst_entry->stages[other_stage].sha);
1425                         dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1426                         try_merge = 0;
1427
1428                         if (sha_eq(src_other.sha1, null_sha1)) {
1429                                 setup_rename_conflict_info(RENAME_DELETE,
1430                                                            ren1->pair,
1431                                                            NULL,
1432                                                            branch1,
1433                                                            branch2,
1434                                                            ren1->dst_entry,
1435                                                            NULL,
1436                                                            o,
1437                                                            NULL,
1438                                                            NULL);
1439                         } else if ((dst_other.mode == ren1->pair->two->mode) &&
1440                                    sha_eq(dst_other.sha1, ren1->pair->two->sha1)) {
1441                                 /*
1442                                  * Added file on the other side identical to
1443                                  * the file being renamed: clean merge.
1444                                  * Also, there is no need to overwrite the
1445                                  * file already in the working copy, so call
1446                                  * update_file_flags() instead of
1447                                  * update_file().
1448                                  */
1449                                 update_file_flags(o,
1450                                                   ren1->pair->two->sha1,
1451                                                   ren1->pair->two->mode,
1452                                                   ren1_dst,
1453                                                   1, /* update_cache */
1454                                                   0  /* update_wd    */);
1455                         } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1456                                 clean_merge = 0;
1457                                 try_merge = 1;
1458                                 output(o, 1, _("CONFLICT (rename/add): Rename %s->%s in %s. "
1459                                        "%s added in %s"),
1460                                        ren1_src, ren1_dst, branch1,
1461                                        ren1_dst, branch2);
1462                                 if (o->call_depth) {
1463                                         struct merge_file_info mfi;
1464                                         mfi = merge_file_one(o, ren1_dst, null_sha1, 0,
1465                                                          ren1->pair->two->sha1, ren1->pair->two->mode,
1466                                                          dst_other.sha1, dst_other.mode,
1467                                                          branch1, branch2);
1468                                         output(o, 1, _("Adding merged %s"), ren1_dst);
1469                                         update_file(o, 0, mfi.sha, mfi.mode, ren1_dst);
1470                                         try_merge = 0;
1471                                 } else {
1472                                         char *new_path = unique_path(o, ren1_dst, branch2);
1473                                         output(o, 1, _("Adding as %s instead"), new_path);
1474                                         update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1475                                         free(new_path);
1476                                 }
1477                         } else
1478                                 try_merge = 1;
1479
1480                         if (try_merge) {
1481                                 struct diff_filespec *one, *a, *b;
1482                                 src_other.path = (char *)ren1_src;
1483
1484                                 one = ren1->pair->one;
1485                                 if (a_renames == renames1) {
1486                                         a = ren1->pair->two;
1487                                         b = &src_other;
1488                                 } else {
1489                                         b = ren1->pair->two;
1490                                         a = &src_other;
1491                                 }
1492                                 update_entry(ren1->dst_entry, one, a, b);
1493                                 setup_rename_conflict_info(RENAME_NORMAL,
1494                                                            ren1->pair,
1495                                                            NULL,
1496                                                            branch1,
1497                                                            NULL,
1498                                                            ren1->dst_entry,
1499                                                            NULL,
1500                                                            o,
1501                                                            NULL,
1502                                                            NULL);
1503                         }
1504                 }
1505         }
1506         string_list_clear(&a_by_dst, 0);
1507         string_list_clear(&b_by_dst, 0);
1508
1509         return clean_merge;
1510 }
1511
1512 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1513 {
1514         return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1515 }
1516
1517 static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
1518 {
1519         void *buf;
1520         enum object_type type;
1521         unsigned long size;
1522         buf = read_sha1_file(sha1, &type, &size);
1523         if (!buf)
1524                 return error(_("cannot read object %s"), sha1_to_hex(sha1));
1525         if (type != OBJ_BLOB) {
1526                 free(buf);
1527                 return error(_("object %s is not a blob"), sha1_to_hex(sha1));
1528         }
1529         strbuf_attach(dst, buf, size, size + 1);
1530         return 0;
1531 }
1532
1533 static int blob_unchanged(const unsigned char *o_sha,
1534                           const unsigned char *a_sha,
1535                           int renormalize, const char *path)
1536 {
1537         struct strbuf o = STRBUF_INIT;
1538         struct strbuf a = STRBUF_INIT;
1539         int ret = 0; /* assume changed for safety */
1540
1541         if (sha_eq(o_sha, a_sha))
1542                 return 1;
1543         if (!renormalize)
1544                 return 0;
1545
1546         assert(o_sha && a_sha);
1547         if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
1548                 goto error_return;
1549         /*
1550          * Note: binary | is used so that both renormalizations are
1551          * performed.  Comparison can be skipped if both files are
1552          * unchanged since their sha1s have already been compared.
1553          */
1554         if (renormalize_buffer(path, o.buf, o.len, &o) |
1555             renormalize_buffer(path, a.buf, o.len, &a))
1556                 ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1557
1558 error_return:
1559         strbuf_release(&o);
1560         strbuf_release(&a);
1561         return ret;
1562 }
1563
1564 static void handle_modify_delete(struct merge_options *o,
1565                                  const char *path,
1566                                  unsigned char *o_sha, int o_mode,
1567                                  unsigned char *a_sha, int a_mode,
1568                                  unsigned char *b_sha, int b_mode)
1569 {
1570         handle_change_delete(o,
1571                              path,
1572                              o_sha, o_mode,
1573                              a_sha, a_mode,
1574                              b_sha, b_mode,
1575                              _("modify"), _("modified"));
1576 }
1577
1578 static int merge_content(struct merge_options *o,
1579                          const char *path,
1580                          unsigned char *o_sha, int o_mode,
1581                          unsigned char *a_sha, int a_mode,
1582                          unsigned char *b_sha, int b_mode,
1583                          struct rename_conflict_info *rename_conflict_info)
1584 {
1585         const char *reason = _("content");
1586         const char *path1 = NULL, *path2 = NULL;
1587         struct merge_file_info mfi;
1588         struct diff_filespec one, a, b;
1589         unsigned df_conflict_remains = 0;
1590
1591         if (!o_sha) {
1592                 reason = _("add/add");
1593                 o_sha = (unsigned char *)null_sha1;
1594         }
1595         one.path = a.path = b.path = (char *)path;
1596         hashcpy(one.sha1, o_sha);
1597         one.mode = o_mode;
1598         hashcpy(a.sha1, a_sha);
1599         a.mode = a_mode;
1600         hashcpy(b.sha1, b_sha);
1601         b.mode = b_mode;
1602
1603         if (rename_conflict_info) {
1604                 struct diff_filepair *pair1 = rename_conflict_info->pair1;
1605
1606                 path1 = (o->branch1 == rename_conflict_info->branch1) ?
1607                         pair1->two->path : pair1->one->path;
1608                 /* If rename_conflict_info->pair2 != NULL, we are in
1609                  * RENAME_ONE_FILE_TO_ONE case.  Otherwise, we have a
1610                  * normal rename.
1611                  */
1612                 path2 = (rename_conflict_info->pair2 ||
1613                          o->branch2 == rename_conflict_info->branch1) ?
1614                         pair1->two->path : pair1->one->path;
1615
1616                 if (dir_in_way(path, !o->call_depth))
1617                         df_conflict_remains = 1;
1618         }
1619         mfi = merge_file_special_markers(o, &one, &a, &b,
1620                                          o->branch1, path1,
1621                                          o->branch2, path2);
1622
1623         if (mfi.clean && !df_conflict_remains &&
1624             sha_eq(mfi.sha, a_sha) && mfi.mode == a_mode) {
1625                 int path_renamed_outside_HEAD;
1626                 output(o, 3, _("Skipped %s (merged same as existing)"), path);
1627                 /*
1628                  * The content merge resulted in the same file contents we
1629                  * already had.  We can return early if those file contents
1630                  * are recorded at the correct path (which may not be true
1631                  * if the merge involves a rename).
1632                  */
1633                 path_renamed_outside_HEAD = !path2 || !strcmp(path, path2);
1634                 if (!path_renamed_outside_HEAD) {
1635                         add_cacheinfo(mfi.mode, mfi.sha, path,
1636                                       0, (!o->call_depth), 0);
1637                         return mfi.clean;
1638                 }
1639         } else
1640                 output(o, 2, _("Auto-merging %s"), path);
1641
1642         if (!mfi.clean) {
1643                 if (S_ISGITLINK(mfi.mode))
1644                         reason = _("submodule");
1645                 output(o, 1, _("CONFLICT (%s): Merge conflict in %s"),
1646                                 reason, path);
1647                 if (rename_conflict_info && !df_conflict_remains)
1648                         update_stages(path, &one, &a, &b);
1649         }
1650
1651         if (df_conflict_remains) {
1652                 char *new_path;
1653                 if (o->call_depth) {
1654                         remove_file_from_cache(path);
1655                 } else {
1656                         if (!mfi.clean)
1657                                 update_stages(path, &one, &a, &b);
1658                         else {
1659                                 int file_from_stage2 = was_tracked(path);
1660                                 struct diff_filespec merged;
1661                                 hashcpy(merged.sha1, mfi.sha);
1662                                 merged.mode = mfi.mode;
1663
1664                                 update_stages(path, NULL,
1665                                               file_from_stage2 ? &merged : NULL,
1666                                               file_from_stage2 ? NULL : &merged);
1667                         }
1668
1669                 }
1670                 new_path = unique_path(o, path, rename_conflict_info->branch1);
1671                 output(o, 1, _("Adding as %s instead"), new_path);
1672                 update_file(o, 0, mfi.sha, mfi.mode, new_path);
1673                 free(new_path);
1674                 mfi.clean = 0;
1675         } else {
1676                 update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1677         }
1678         return mfi.clean;
1679
1680 }
1681
1682 /* Per entry merge function */
1683 static int process_entry(struct merge_options *o,
1684                          const char *path, struct stage_data *entry)
1685 {
1686         /*
1687         printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1688         print_index_entry("\tpath: ", entry);
1689         */
1690         int clean_merge = 1;
1691         int normalize = o->renormalize;
1692         unsigned o_mode = entry->stages[1].mode;
1693         unsigned a_mode = entry->stages[2].mode;
1694         unsigned b_mode = entry->stages[3].mode;
1695         unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1696         unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1697         unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1698
1699         entry->processed = 1;
1700         if (entry->rename_conflict_info) {
1701                 struct rename_conflict_info *conflict_info = entry->rename_conflict_info;
1702                 switch (conflict_info->rename_type) {
1703                 case RENAME_NORMAL:
1704                 case RENAME_ONE_FILE_TO_ONE:
1705                         clean_merge = merge_content(o, path,
1706                                                     o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1707                                                     conflict_info);
1708                         break;
1709                 case RENAME_DELETE:
1710                         clean_merge = 0;
1711                         conflict_rename_delete(o, conflict_info->pair1,
1712                                                conflict_info->branch1,
1713                                                conflict_info->branch2);
1714                         break;
1715                 case RENAME_ONE_FILE_TO_TWO:
1716                         clean_merge = 0;
1717                         conflict_rename_rename_1to2(o, conflict_info);
1718                         break;
1719                 case RENAME_TWO_FILES_TO_ONE:
1720                         clean_merge = 0;
1721                         conflict_rename_rename_2to1(o, conflict_info);
1722                         break;
1723                 default:
1724                         entry->processed = 0;
1725                         break;
1726                 }
1727         } else if (o_sha && (!a_sha || !b_sha)) {
1728                 /* Case A: Deleted in one */
1729                 if ((!a_sha && !b_sha) ||
1730                     (!b_sha && blob_unchanged(o_sha, a_sha, normalize, path)) ||
1731                     (!a_sha && blob_unchanged(o_sha, b_sha, normalize, path))) {
1732                         /* Deleted in both or deleted in one and
1733                          * unchanged in the other */
1734                         if (a_sha)
1735                                 output(o, 2, _("Removing %s"), path);
1736                         /* do not touch working file if it did not exist */
1737                         remove_file(o, 1, path, !a_sha);
1738                 } else {
1739                         /* Modify/delete; deleted side may have put a directory in the way */
1740                         clean_merge = 0;
1741                         handle_modify_delete(o, path, o_sha, o_mode,
1742                                              a_sha, a_mode, b_sha, b_mode);
1743                 }
1744         } else if ((!o_sha && a_sha && !b_sha) ||
1745                    (!o_sha && !a_sha && b_sha)) {
1746                 /* Case B: Added in one. */
1747                 /* [nothing|directory] -> ([nothing|directory], file) */
1748
1749                 const char *add_branch;
1750                 const char *other_branch;
1751                 unsigned mode;
1752                 const unsigned char *sha;
1753                 const char *conf;
1754
1755                 if (a_sha) {
1756                         add_branch = o->branch1;
1757                         other_branch = o->branch2;
1758                         mode = a_mode;
1759                         sha = a_sha;
1760                         conf = _("file/directory");
1761                 } else {
1762                         add_branch = o->branch2;
1763                         other_branch = o->branch1;
1764                         mode = b_mode;
1765                         sha = b_sha;
1766                         conf = _("directory/file");
1767                 }
1768                 if (dir_in_way(path, !o->call_depth)) {
1769                         char *new_path = unique_path(o, path, add_branch);
1770                         clean_merge = 0;
1771                         output(o, 1, _("CONFLICT (%s): There is a directory with name %s in %s. "
1772                                "Adding %s as %s"),
1773                                conf, path, other_branch, path, new_path);
1774                         if (o->call_depth)
1775                                 remove_file_from_cache(path);
1776                         update_file(o, 0, sha, mode, new_path);
1777                         if (o->call_depth)
1778                                 remove_file_from_cache(path);
1779                         free(new_path);
1780                 } else {
1781                         output(o, 2, _("Adding %s"), path);
1782                         /* do not overwrite file if already present */
1783                         update_file_flags(o, sha, mode, path, 1, !a_sha);
1784                 }
1785         } else if (a_sha && b_sha) {
1786                 /* Case C: Added in both (check for same permissions) and */
1787                 /* case D: Modified in both, but differently. */
1788                 clean_merge = merge_content(o, path,
1789                                             o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1790                                             NULL);
1791         } else if (!o_sha && !a_sha && !b_sha) {
1792                 /*
1793                  * this entry was deleted altogether. a_mode == 0 means
1794                  * we had that path and want to actively remove it.
1795                  */
1796                 remove_file(o, 1, path, !a_mode);
1797         } else
1798                 die(_("Fatal merge failure, shouldn't happen."));
1799
1800         return clean_merge;
1801 }
1802
1803 int merge_trees(struct merge_options *o,
1804                 struct tree *head,
1805                 struct tree *merge,
1806                 struct tree *common,
1807                 struct tree **result)
1808 {
1809         int code, clean;
1810
1811         if (o->subtree_shift) {
1812                 merge = shift_tree_object(head, merge, o->subtree_shift);
1813                 common = shift_tree_object(head, common, o->subtree_shift);
1814         }
1815
1816         if (sha_eq(common->object.sha1, merge->object.sha1)) {
1817                 output(o, 0, _("Already up-to-date!"));
1818                 *result = head;
1819                 return 1;
1820         }
1821
1822         code = git_merge_trees(o->call_depth, common, head, merge);
1823
1824         if (code != 0) {
1825                 if (show(o, 4) || o->call_depth)
1826                         die(_("merging of trees %s and %s failed"),
1827                             sha1_to_hex(head->object.sha1),
1828                             sha1_to_hex(merge->object.sha1));
1829                 else
1830                         exit(128);
1831         }
1832
1833         if (unmerged_cache()) {
1834                 struct string_list *entries, *re_head, *re_merge;
1835                 int i;
1836                 string_list_clear(&o->current_file_set, 1);
1837                 string_list_clear(&o->current_directory_set, 1);
1838                 get_files_dirs(o, head);
1839                 get_files_dirs(o, merge);
1840
1841                 entries = get_unmerged();
1842                 record_df_conflict_files(o, entries);
1843                 re_head  = get_renames(o, head, common, head, merge, entries);
1844                 re_merge = get_renames(o, merge, common, head, merge, entries);
1845                 clean = process_renames(o, re_head, re_merge);
1846                 for (i = entries->nr-1; 0 <= i; i--) {
1847                         const char *path = entries->items[i].string;
1848                         struct stage_data *e = entries->items[i].util;
1849                         if (!e->processed
1850                                 && !process_entry(o, path, e))
1851                                 clean = 0;
1852                 }
1853                 for (i = 0; i < entries->nr; i++) {
1854                         struct stage_data *e = entries->items[i].util;
1855                         if (!e->processed)
1856                                 die(_("Unprocessed path??? %s"),
1857                                     entries->items[i].string);
1858                 }
1859
1860                 string_list_clear(re_merge, 0);
1861                 string_list_clear(re_head, 0);
1862                 string_list_clear(entries, 1);
1863
1864         }
1865         else
1866                 clean = 1;
1867
1868         if (o->call_depth)
1869                 *result = write_tree_from_memory(o);
1870
1871         return clean;
1872 }
1873
1874 static struct commit_list *reverse_commit_list(struct commit_list *list)
1875 {
1876         struct commit_list *next = NULL, *current, *backup;
1877         for (current = list; current; current = backup) {
1878                 backup = current->next;
1879                 current->next = next;
1880                 next = current;
1881         }
1882         return next;
1883 }
1884
1885 /*
1886  * Merge the commits h1 and h2, return the resulting virtual
1887  * commit object and a flag indicating the cleanness of the merge.
1888  */
1889 int merge_recursive(struct merge_options *o,
1890                     struct commit *h1,
1891                     struct commit *h2,
1892                     struct commit_list *ca,
1893                     struct commit **result)
1894 {
1895         struct commit_list *iter;
1896         struct commit *merged_common_ancestors;
1897         struct tree *mrtree = mrtree;
1898         int clean;
1899
1900         if (show(o, 4)) {
1901                 output(o, 4, _("Merging:"));
1902                 output_commit_title(o, h1);
1903                 output_commit_title(o, h2);
1904         }
1905
1906         if (!ca) {
1907                 ca = get_merge_bases(h1, h2, 1);
1908                 ca = reverse_commit_list(ca);
1909         }
1910
1911         if (show(o, 5)) {
1912                 unsigned cnt = commit_list_count(ca);
1913
1914                 output(o, 5, Q_("found %u common ancestor:",
1915                                 "found %u common ancestors:", cnt), cnt);
1916                 for (iter = ca; iter; iter = iter->next)
1917                         output_commit_title(o, iter->item);
1918         }
1919
1920         merged_common_ancestors = pop_commit(&ca);
1921         if (merged_common_ancestors == NULL) {
1922                 /* if there is no common ancestor, use an empty tree */
1923                 struct tree *tree;
1924
1925                 tree = lookup_tree(EMPTY_TREE_SHA1_BIN);
1926                 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1927         }
1928
1929         for (iter = ca; iter; iter = iter->next) {
1930                 const char *saved_b1, *saved_b2;
1931                 o->call_depth++;
1932                 /*
1933                  * When the merge fails, the result contains files
1934                  * with conflict markers. The cleanness flag is
1935                  * ignored, it was never actually used, as result of
1936                  * merge_trees has always overwritten it: the committed
1937                  * "conflicts" were already resolved.
1938                  */
1939                 discard_cache();
1940                 saved_b1 = o->branch1;
1941                 saved_b2 = o->branch2;
1942                 o->branch1 = "Temporary merge branch 1";
1943                 o->branch2 = "Temporary merge branch 2";
1944                 merge_recursive(o, merged_common_ancestors, iter->item,
1945                                 NULL, &merged_common_ancestors);
1946                 o->branch1 = saved_b1;
1947                 o->branch2 = saved_b2;
1948                 o->call_depth--;
1949
1950                 if (!merged_common_ancestors)
1951                         die(_("merge returned no commit"));
1952         }
1953
1954         discard_cache();
1955         if (!o->call_depth)
1956                 read_cache();
1957
1958         o->ancestor = "merged common ancestors";
1959         clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1960                             &mrtree);
1961
1962         if (o->call_depth) {
1963                 *result = make_virtual_commit(mrtree, "merged tree");
1964                 commit_list_insert(h1, &(*result)->parents);
1965                 commit_list_insert(h2, &(*result)->parents->next);
1966         }
1967         flush_output(o);
1968         if (show(o, 2))
1969                 diff_warn_rename_limit("merge.renamelimit",
1970                                        o->needed_rename_limit, 0);
1971         return clean;
1972 }
1973
1974 static struct commit *get_ref(const unsigned char *sha1, const char *name)
1975 {
1976         struct object *object;
1977
1978         object = deref_tag(parse_object(sha1), name, strlen(name));
1979         if (!object)
1980                 return NULL;
1981         if (object->type == OBJ_TREE)
1982                 return make_virtual_commit((struct tree*)object, name);
1983         if (object->type != OBJ_COMMIT)
1984                 return NULL;
1985         if (parse_commit((struct commit *)object))
1986                 return NULL;
1987         return (struct commit *)object;
1988 }
1989
1990 int merge_recursive_generic(struct merge_options *o,
1991                             const unsigned char *head,
1992                             const unsigned char *merge,
1993                             int num_base_list,
1994                             const unsigned char **base_list,
1995                             struct commit **result)
1996 {
1997         int clean, index_fd;
1998         struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1999         struct commit *head_commit = get_ref(head, o->branch1);
2000         struct commit *next_commit = get_ref(merge, o->branch2);
2001         struct commit_list *ca = NULL;
2002
2003         if (base_list) {
2004                 int i;
2005                 for (i = 0; i < num_base_list; ++i) {
2006                         struct commit *base;
2007                         if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
2008                                 return error(_("Could not parse object '%s'"),
2009                                         sha1_to_hex(base_list[i]));
2010                         commit_list_insert(base, &ca);
2011                 }
2012         }
2013
2014         index_fd = hold_locked_index(lock, 1);
2015         clean = merge_recursive(o, head_commit, next_commit, ca,
2016                         result);
2017         if (active_cache_changed &&
2018                         (write_cache(index_fd, active_cache, active_nr) ||
2019                          commit_locked_index(lock)))
2020                 return error(_("Unable to write index."));
2021
2022         return clean ? 0 : 1;
2023 }
2024
2025 static int merge_recursive_config(const char *var, const char *value, void *cb)
2026 {
2027         struct merge_options *o = cb;
2028         if (!strcmp(var, "merge.verbosity")) {
2029                 o->verbosity = git_config_int(var, value);
2030                 return 0;
2031         }
2032         if (!strcmp(var, "diff.renamelimit")) {
2033                 o->diff_rename_limit = git_config_int(var, value);
2034                 return 0;
2035         }
2036         if (!strcmp(var, "merge.renamelimit")) {
2037                 o->merge_rename_limit = git_config_int(var, value);
2038                 return 0;
2039         }
2040         return git_xmerge_config(var, value, cb);
2041 }
2042
2043 void init_merge_options(struct merge_options *o)
2044 {
2045         memset(o, 0, sizeof(struct merge_options));
2046         o->verbosity = 2;
2047         o->buffer_output = 1;
2048         o->diff_rename_limit = -1;
2049         o->merge_rename_limit = -1;
2050         o->renormalize = 0;
2051         git_config(merge_recursive_config, o);
2052         if (getenv("GIT_MERGE_VERBOSITY"))
2053                 o->verbosity =
2054                         strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
2055         if (o->verbosity >= 5)
2056                 o->buffer_output = 0;
2057         strbuf_init(&o->obuf, 0);
2058         memset(&o->current_file_set, 0, sizeof(struct string_list));
2059         o->current_file_set.strdup_strings = 1;
2060         memset(&o->current_directory_set, 0, sizeof(struct string_list));
2061         o->current_directory_set.strdup_strings = 1;
2062         memset(&o->df_conflict_file_set, 0, sizeof(struct string_list));
2063         o->df_conflict_file_set.strdup_strings = 1;
2064 }
2065
2066 int parse_merge_opt(struct merge_options *o, const char *s)
2067 {
2068         if (!s || !*s)
2069                 return -1;
2070         if (!strcmp(s, "ours"))
2071                 o->recursive_variant = MERGE_RECURSIVE_OURS;
2072         else if (!strcmp(s, "theirs"))
2073                 o->recursive_variant = MERGE_RECURSIVE_THEIRS;
2074         else if (!strcmp(s, "subtree"))
2075                 o->subtree_shift = "";
2076         else if (starts_with(s, "subtree="))
2077                 o->subtree_shift = s + strlen("subtree=");
2078         else if (!strcmp(s, "patience"))
2079                 o->xdl_opts = DIFF_WITH_ALG(o, PATIENCE_DIFF);
2080         else if (!strcmp(s, "histogram"))
2081                 o->xdl_opts = DIFF_WITH_ALG(o, HISTOGRAM_DIFF);
2082         else if (starts_with(s, "diff-algorithm=")) {
2083                 long value = parse_algorithm_value(s + strlen("diff-algorithm="));
2084                 if (value < 0)
2085                         return -1;
2086                 /* clear out previous settings */
2087                 DIFF_XDL_CLR(o, NEED_MINIMAL);
2088                 o->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
2089                 o->xdl_opts |= value;
2090         }
2091         else if (!strcmp(s, "ignore-space-change"))
2092                 o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2093         else if (!strcmp(s, "ignore-all-space"))
2094                 o->xdl_opts |= XDF_IGNORE_WHITESPACE;
2095         else if (!strcmp(s, "ignore-space-at-eol"))
2096                 o->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2097         else if (!strcmp(s, "renormalize"))
2098                 o->renormalize = 1;
2099         else if (!strcmp(s, "no-renormalize"))
2100                 o->renormalize = 0;
2101         else if (starts_with(s, "rename-threshold=")) {
2102                 const char *score = s + strlen("rename-threshold=");
2103                 if ((o->rename_score = parse_rename_score(&score)) == -1 || *score != 0)
2104                         return -1;
2105         }
2106         else
2107                 return -1;
2108         return 0;
2109 }